1. Field of the Invention
The present invention relates to a method for controlling defective sectors of disk drive recording devices, and more particularly a method for controlling a data reading/writing operation on random data sections containing defective sectors.
2. Description of the Related Art
Disk drive recording devices, such as a hard disk drive and a floppy disk drive, are widely used as auxiliary storage devices for computer systems. Especially, the hard disk drive not only has a capacity to stably store a large amount of data, but also makes it possible to access stored data at a great speed, and accordingly has been rapidly popularized. Recently, since multimedia devices have rapidly spread, the audio/video disk drives must maintain a data transfer rate at least above a specified speed. One of the methods for meeting the above requirement is to control the defective sectors on the disks. The earlier widely used method for controlling the defective sectors on disk drive recording devices is explained below for a hard disk drive.
Generally, there are two methods for controlling defective sectors of hard disk drives. The one method is the sector slipping method in which, when a defect is detected in one of the consecutive data sectors (hereinafter referred to as a "sector"), the following sector next to the defective sector is used as the consecutive sector next to the preceding valid sector by setting aside the defective sector (see FIG. 1A). Another method is the re-allocation of a reserved sector substituting for the defective sector in which, when a defective sector is detected on one of the tracks of disks, a reserve sector on one of the tracks is re-allocated to substitute for the defective sector. The number of reserve sectors on any optional track is determined according to the designer's intention, and the entire span of a specified track can be set aside as a reserve sector track (see FIGS. 1B and 1C).
The second defective sector control method has a drawback in that the data read time is delayed. To explain in detail, when reading a data section containing a defective sector, at first the read/write head reads the sectors preceding the defective sector, and then moves to the reserve sector re-allocated as a substitute for the defective sector to read data, and finally reads again the following sectors next to the defective sector, which results in requiring unnecessary additional track seek time. In other words, when reading data written on a data section containing defective sector(s), it is a problem in that the additional time (track seeking time+object sector following time) is required unnecessarily. As a result, the disk drives at first satisfy the audio/video drive condition at the time of delivery, but are gradually deprived of the satisfaction of the above condition due to the defective sectors formed with the passage of time.
Each of the following patents disclose features in common with the present invention but do not teach or suggest a method for controlling data reading/writing on a random data section containing a defective sector as in the present invention: U.S. Pat. No. 5,271,018 to Chan, entitled Method And Apparatus For Media Defect Management And Media Addressing, U.S. Pat. No. 5,339,319 to Yamane et al., entitled Rotary Type Storage Apparatus And Control Method Thereof, U.S. Pat. No. 5,442,193 to Shih et al., entitled Data Recording System Having Improved Bookkeeping Capability, U.S. Pat. No. 5,357,381 to Yasuda et al., entitled Flexible Magnetic Disc Drive Apparatus For Designating Alternate Sectors For Defective Sectors, U.S. Pat. No. 5,258,852 to Kamijima, entitled Recording Medium And Video Signal Recording/Reproducing Method Using A Predetermined Area Of A Recording Medium To Record Information Intended To Be Recorded In A Defective Portion Of The Medium, U.S. Pat. No. 5,166,936 to Ewert et al., entitled Automatic Hard Disk Bad Sector Remapping, U.S. Pat. No. 5,202,876 to Takagi et al., entitled Optical Disc Recording-Reproducing Apparatus In Which Sector Substitution Of Defective Sectors Is Performed, U.S. Pat. No. 5,666,335 to Horibe, entitled Apparatus And Method For Correcting For Defective Sectors In A Recording Medium, U.S. Pat. No. 4,986,668 to Fukushima et al, entitled Information Recording And Reproducing Apparatus With Management Of Defective Sector, U.S. Pat. No. 4,405,952 to Slakmon, entitled Apparatus For Detecting Faulty Sectors And For Allocating Replacement Sectors In A Magnetic Disk Memory, U.S. Pat. No. 5,241,531 to Ohno et al., entitled Storage Medium Having Read/Write Storage Region And Read-Only Storage Region And A Method For Managing Defective Sectors In The Storage Medium, and U.S. Pat. No. 5,111,444 to Fukushima et al, entitled Method Of Managing Defective Sectors In A Disk-Shaped Information Recording Medium And AN Apparatus For Performing The Same.